1. Field of the Invention
This invention relates to the field of telecommunications and in particular to antenna systems and operational methods.
2. Description of the Prior Art
Antennas are used to receive and transmit signals that comprise electromagnetic waveforms. In many instances, a single antenna is used to either receive or transmit an individual signal. A single antenna can be configured to simultaneously transmit and receive signals. A current practice for combining transmit and receive capabilities into a single antenna includes using a filter/combiner. An example of a filter/combiner includes radio frequency (RF) circuitry that combines a received signal with a transmitted signal into a single antenna feed line and filters the received signal.
The current practice of using a filter/combiner requires mounting the filter/combiner either at a base of an antenna platform or directly behind an antenna. When located at the base of the antenna platform, a number of coaxial cables providing antenna feed lines is reduced. However, locating the filter/combiner at the base of the antenna platform precludes advantages of a Low Noise Amplifier (LNA) mounted directly behind the antenna. The advantages of an LNA mounted directly behind the antenna include amplification of a signal that is received by the antenna.
An LNA can be used if the filter/combiner is mounted directly behind the antenna. However, mounting the filter/combiner directly behind the antenna increases a number of antenna feed lines. For example, a first coaxial cable from the antenna to a receiver in an equipment shelter provides reception capabilities and a second coaxial cable from a transmitter in the equipment shelter provides transmission capabilities.
Combining reception and transmission capabilities into a single antenna reduces a number of antennas in a communication system. Reducing the number of antennas is advantageous as it reduces costs associated with purchases and designs of the antennas. Reducing the number of antennas also reduces a physical load placed on an antenna support structure. Unfortunately, the prior solutions of combining reception and transmission capabilities either do not take advantage of an LNA or increase a number of antenna feed lines.